Console
    Contact Us Start free

    Class Session (3.0.0) 

      Session 
 ( 
 database 
 , 
 labels 
 = 
 None 
 )

    Representation of a Cloud Spanner Session.

    We can use a Session to:

    • create the session
    • Use exists to check for the existence of the session
    • drop the session

    Parameters

    Name
    Description
    database
    Database

    The database to which the session is bound.

    labels
    dict (str -> str)

    (Optional) User-assigned labels for the session.

    Properties

    labels

    User-assigned labels for the session.

    Returns
    Type
    Description
    dict (str -> str)
    the labels dict (empty if no labels were assigned.

    name

    Session name used in requests.

    "projects/../instances/../databases/../sessions/{session_id}"
    Exceptions
    Type
    Description
    ValueError
    if session is not yet created
    Returns
    Type
    Description
    str
    The session name.

    session_id

    Read-only ID, set by the back-end during create .

    Methods

    batch

      batch 
 ()

    Factory to create a batch for this session.

    Exceptions
    Type
    Description
    ValueError
    if the session has not yet been created.
    Returns
    Type
    Description
    Batch
    a batch bound to this session

    create

      create 
 ()

    Create this session, bound to its database.

    See https://cloud.google.com/spanner/reference/rpc/google.spanner.v1#google.spanner.v1.Spanner.CreateSession

    Exceptions
    Type
    Description
    `ValueError
    if session_id is already set.

    delete

      delete 
 ()

    Delete this session.

    See https://cloud.google.com/spanner/reference/rpc/google.spanner.v1#google.spanner.v1.Spanner.GetSession

    Exceptions
    Type
    Description
    ValueError
    if session_id is not already set.
    NotFound
    if the session does not exist

    execute_sql

      execute_sql 
 ( 
 sql 
 , 
 params 
 = 
 None 
 , 
 param_types 
 = 
 None 
 , 
 query_mode 
 = 
 None 
 , 
 query_options 
 = 
 None 
 , 
 retry 
 = 
< _MethodDefault 
 . 
 _DEFAULT_VALUE 
 : 
< object 
 object 
>> , 
 timeout 
 = 
< _MethodDefault 
 . 
 _DEFAULT_VALUE 
 : 
< object 
 object 
>> )

    Perform an ExecuteStreamingSql API request.

    Parameters
    Name
    Description
    sql
    str

    SQL query statement

    params
    dict, {str -> column value}

    values for parameter replacement. Keys must match the names used in sql .

    param_types
    dict, {str -> google.spanner.v1.type_pb2.TypeCode }

    (Optional) explicit types for one or more param values; overrides default type detection on the back-end.

    query_mode
    google.spanner.v1.spanner_pb2.ExecuteSqlRequest.QueryMode

    Mode governing return of results / query plan. See: QueryMode https://cloud.google.com/spanner/reference/rpc/google.spanner.v1#google.spanner.v1.ExecuteSqlRequest.QueryMode _.

    query_options
    QueryOptions or dict

    (Optional) Options that are provided for query plan stability.

    Returns
    Type
    Description
    StreamedResultSet
    a result set instance which can be used to consume rows.

    exists

      exists 
 ()

    Test for the existence of this session.

    See https://cloud.google.com/spanner/reference/rpc/google.spanner.v1#google.spanner.v1.Spanner.GetSession

    Returns
    Type
    Description
    bool
    True if the session exists on the back-end, else False.

    ping

      ping 
 ()

    Ping the session to keep it alive by executing "SELECT 1".

    Exceptions
    Type
    Description
    ValueError
    if session_id is not already set.

    read

      read 
 ( 
 table 
 , 
 columns 
 , 
 keyset 
 , 
 index 
 = 
 "" 
 , 
 limit 
 = 
 0 
 )

    Perform a StreamingRead API request for rows in a table.

    Parameters
    Name
    Description
    table
    str

    name of the table from which to fetch data

    columns
    list of str

    names of columns to be retrieved

    keyset
    KeySet

    keys / ranges identifying rows to be retrieved

    index
    str

    (Optional) name of index to use, rather than the table's primary key

    limit
    int

    (Optional) maximum number of rows to return

    Returns
    Type
    Description
    StreamedResultSet
    a result set instance which can be used to consume rows.

    run_in_transaction

      run_in_transaction 
 ( 
 func 
 , 
 * 
 args 
 , 
 ** 
 kw 
 )

    Perform a unit of work in a transaction, retrying on abort.

    Parameters
    Name
    Description
    args
    tuple

    additional positional arguments to be passed to func .

    kw
    dict

    (Optional) keyword arguments to be passed to func . If passed, "timeout_secs" will be removed and used to override the default retry timeout which defines maximum timestamp to continue retrying the transaction.

    func
    callable

    takes a required positional argument, the transaction, and additional positional / keyword arguments as supplied by the caller.

    Exceptions
    Type
    Description
    Exception
    reraises any non-ABORT execptions raised by func .
    Returns
    Type
    Description
    Any
    The return value of func .

    snapshot

      snapshot 
 ( 
 ** 
 kw 
 )

    Create a snapshot to perform a set of reads with shared staleness.

    See https://cloud.google.com/spanner/reference/rpc/google.spanner.v1#google.spanner.v1.TransactionOptions.ReadOnly

    Parameter
    Name
    Description
    kw
    dict

    Passed through to Snapshot ctor.

    Exceptions
    Type
    Description
    ValueError
    if the session has not yet been created.
    Returns
    Type
    Description
    Snapshot
    a snapshot bound to this session

    transaction

      transaction 
 ()

    Create a transaction to perform a set of reads with shared staleness.

    Exceptions
    Type
    Description
    ValueError
    if the session has not yet been created.
    Returns
    Type
    Description
    Transaction
    a transaction bound to this session
    Create a Mobile Website
    View Site in Mobile | Classic
    Share by: